In the related art, there are known laser-scanning microscopes (LSM) whose operation is controlled by an application program executed by a CPU provided in a computer. The application program manages a time flow in which control items, such as image acquisitions, performed by the LSM are set along a time axis. The CPU also executes other software at the same time as the application program. Therefore, variations in the execution time of each control item relative to the set time flow are in 100 millisecond units, which is so large that the time precision is insufficient for observing reactions in biological cell etc., which are on the order of 1 millisecond.
In order to cope with such a problem, there are known laser-scanning microscopes that are configured such that a computer is provided with a software sequencer that operates independently of a CPU, and some of the functions that have been executed by a conventional CPU are executed by the software sequencer (for example, see PTL 1). The software sequencer described in PTL 1 executes a preset time flow, and it is not expected to change the conditions of the individual control items during execution of the time flow.